When producing natural gas for delivery via for instance a gas conduit, the natural gas is received from the source at a very high pressure. The natural gas comprises larger or smaller amounts of undesired substances, such as oil, water, heavier hydrocarbons etc., in the form of liquid particles. Before delivery of the natural gas, for instance via a pipe line, the gas has to be treated and undesired substances, such as oil, be removed. Thereafter, the pressure has to be reduced to a manageable level. Today separating members in the form of so-called scrubbers for separating oil from the natural gas are used. The expression fossil gas mixture can in the present application refer to natural gas. The expression may also refer to the gas or gas mixture which is obtained during production of oil from natural oil sources. Such a gas or gas mixture may contain large amounts of liquid particles.
WO 2008/111909 discloses a particle separator for separating particles from a gas mixture. The separator comprises a stationary casing, defining a separation space permitting a gas flow therethrough, and an inlet for the gas mixture through the casing into the separation space. A rotation member is provided in the separation space downstream the inlet with respect to the gas flow and arranged to cause the gas mixture to rotate. A separating member for separating the gas mixture comprises a spindle with a plurality of separating discs and is provided in the separation space downstream the rotation member with respect to the gas flow. A drive motor is connected to the spindle and arranged, during the separation, to rotate the separating member via the spindle in a direction of rotation about an axis of rotation at a number of revolutions lying within a range of revolutions. The separating member is configured to separate particles from the gas mixture by means of centrifugal forces. Furthermore, a gas outlet is provided downstream the separating member with respect to the gas flow for discharge of the separated gas. An oil outlet for discharge of oil extends through the casing. The separator disclosed is not suitable for treating a fossil gas mixture, and especially not for separating oil from the fossil gas mixture.
U.S. Pat. No. 4,687,585 discloses a plant and a method for separating at least one component from a fossil fluid, such as crude oil or natural gas, during utilization of a device comprising a centrifuge rotor. The centrifuge rotor in the known device comprises a central hollow inlet chamber and a number of conical separating discs. The fossil fluid is conveyed centrally into the central chamber and then flows radially outwardly in the interspaces between the separating discs.
U.S. Pat. No. 5,755,096 discloses a dynamic filter arranged to be connected to a natural gas source. The dynamic filter comprises a stationary casing with a rotating separating rotor comprising separating discs extending mainly axially. The separating member seems to driven by means of the flow of natural gas.
FR-A-2 476 505 discloses a cyclone for separating particles from a gas. The cyclone comprises a rotor member, which comprises a number of discs and which is provided in the cyclone immediately inside the outlet of the cyclone for cleaned gas.
SE-525 432 discloses a centrifugal separator for cleaning of pressurised air from a compressor and to a brake system of a motor vehicle. The centrifugal separator is arranged to remove impurities from the compressor.